Foldable boat

ABSTRACT

A foldable boat comprises a frame and a flexible cover. The flexible cover is secured to the sides of the boat and around the nose thereof and across the ends of the sides; and it is also secured to a rigid keel which extends from fore to aft of the boat. A transom plate is rigidly secured to the keel, and the transom may be placed between the ends of the sides and lifted to be secured to the transom plate so that the bottom of the boat, which is formed by the flexible cover, is contoured. Thwarts are provided to extend across the width of the boat at various places along its length, and the dimensions of the thwarts govern the sideways spacing between the sides of the boat at those places. Floorboards are supported by the rigid keel and by supporting lugs at the lower edges of the side members, and serve to maintain the sideways spacing of the lower edges of the sides.

United States Patent 1 Musson July 31, 1973 FOLDABLE BOAT [76] Inventor:William F. J. Musson, 391 Sentinel Rd., Apt. 118, Downsview, Ontario,Canada [22] Filed: May 28, 1,971

[21] Appl. No.: 147,761

[52] US. Cl 9/2 C, 9/2 F [51] Int. Cl B63b 7/06 [58] Field of Search 9/2R, 2 C, 2 F, 9/2 S, 7

[56] References Cited UNITED STATES PATENTS 3,071,785 l/l963 Holt 9/2 C3,383,719 5/1968 l-leide..-. 9/2 C Primary Examiner-Milton BuchlerAssistant E FQT 'WFTCQlA R l AttorneyDouglas S. Johnson [5 7] ABSTRACT Afoldable boat comprises a frame and a flexible cover.

' The flexible cover is secured to the sides of the boat and around thenose thereof and across the ends of the sides; and it is also secured toa rigid keel which extends from fore to aft of the boat. A transom plateis rigidly secured to the keel, and the transom may be placed betweenthe ends of the sides and lifted to be secured to the transom plate sothat the bottom of the boat, which is formed by the flexible cover, iscontoured. Thwarts are provided to extend across the width of the boatat various places along its length, and the dimensions of the thwartsgovern the sideways spacing between the sides of the boat at thoseplaces. Floorboards are supported by the rigid keel and by supportinglugs at the lower edges. of the side members, and serve to maintain thesideways spacing of the lower edges of the sides.

4 Claims, 11 Drawing Figures PATENTED 1 3. 748.670

SHEET 1 BF 3 INVENTOR. WILLIAM F. J MUS SON PATENTED M I915 3; 748.670

SHEET 3 0F 3 FOLDABLE BOAT BACKGROUND OF THE INVENTION This inventionrelates to a foldable boat. In particular, this invention teaches afoldable boat whose width, when folded, is substantially less than itswidth when assembled. The foldable boat comprises a substantially rigidframe, except for the sides which are flexible, and a flexible,water-proof cover fitted over the frame and attached to it. The foldableboat of this invention is adapted to be disassembled and placed in acarrying case or binding so that it may be easily handled by one person.

In the past few years, the style of living for many persons has changed;in that many families now live in apartments and other lodgings wherestorage space for recreational equipment may be somewhat limited. Manypersons and families take their recreation by going away from the urbanor suburban residential areas in which they live to countryside areaswhere they may indulge in such activities as boating, fishing andcamping. Such activities have greatly increased since most cottage,resort and recreational areas are now easily accessible from most urbancentres.

Because of the nature of the style of living of many persons, thelimited capital which may be available to most families, and the lengthof time available for holiday or recreational activities, it has becomevery desirable to many persons and families to have possession of a boatwhich can be taken out onto bodies of water such as lakes and riverswhich may be accessible from cottage, resort or other recreationalareas. Of course, the boat should be such that it may be easily carriedfrom one place to another, and easily stored when not in use. The boatmust also be easily assembled, lightweight, and relatively inexpensive.

There have, in the past, been different sorts of boats available forrecreational use. One of the most popular sorts of boats has been thecar-topper, which is a stamped, deep drawn or moulded aluminum boat.Such boats are not usually available in greater length that 12 or l4feet, and even at those lengths an aluminum boat may be quite heavy, andfairly expensive. Other types of boats that have been available includecanoes and kayaks, inflatable rafts and dinghies, and other small craftwhich may be either carried on a rack on top of a normal automobile, ortowed behind an automobile on a trailer.

A disadvantage of many sorts of boats such as canoes and kayaks, despitetheir light-weight and relatively low cost, is that such boats are notnormally adapted to carry more than one or two persons, nor are theyadapted to be powered by a light-weight, portable outboard engine.Therefore, there have been few boats which have been commerciallyavailable and which satisfy all of the criteria that they belight-weight, relatively inexpensive, easily stored,.portable, andcapable of being powered by an outboard engine.

Still further, many persons are desirous of obtaining small,light-weight boats which may be used as sail boats; and it is a featuredalternative of the present invention that a foldable boat according tothis invention can be easily adapted to be used as a sail boat.

Foldable or collapsible boats have been known in the past, but most ofthose boats have been such that a very complicated frame structureusually tubular metal has been provided, which, when assembled, must bethen covered with a tight skin. The strength of the boat, when floatingupright in water and loaded with passengers and/or freight, is derivedfrom the frame of the boat, and the water tightness (buoyancy) of theboat has been derived from the skin. Still further, collapsible boatswhich have been known such as those in US.

Pat. No. 1,231,924 issued July 3, 1917 to L. L. McGee, or US Pat. No.3,383,719 issued May 21, 1968 to Van der Heide, have not offered a rigidtransom nor a rigid keel, so that the strength and rigidity of the boatmust be derived from the frame and not from a combination of the frameacting with the skin or water-tight covering of the boat.

Very often in the past, recreational products which have been availableon the market, including collapsible or foldable boats, simple vehicles,exercise equipment, etc., has required considerable time and/or specialskill and/or special tools in order to be assembled properly. Thus, thevaried advantages of light-weight and low cost which have been offeredby certain recreational facilities including collapsible boats in thepast have been offset by the difficulty in assembling them.

SUMMARY OF THE INVENTION It is a purpose of this invention to provide afoldable boat which is easily carried in its folded state, which may beeasily assembled without special tools, and which is relativelylight-weight and inexpensive.

A further object of this invention is to provide a foldable boat whereinthe strength and buoyancy of vthe boat together are derived from thecombination of the rigid, assembled frame of the boat and the flexible,water-tight cover therefor, each acting in co-operation with the other.

Yet a further object of this invention isto provide a foldable boatwhich may be powered by a light-weight portable, outboard engine; andwhich may be adapted to be powered by sail.

BRIEF DESCRIPTION OF THE DRAWINGS These and other features and objectsof the invention are more clearly discussed hereafter in associationwith the accompanying drawings, in which:

FIG. 1 is a perspective view of an assembled, foldable boat according tothis invention;

FIG. 2 is a perspective view of a disassembled, foldable boat accordingto this invention; and a carrying case therefor;

FIG. 3 is a perspective view of the nose of the foldable boat of thisinvention;

FIG. 4 is a perspective view illustrating a step in the assembly of thefoldable boat, at the nose thereof;

FIG. 5 is a. perspective view illustrating a further step in theassembly of the foldable boat, at the stern or transom thereof;

FIG. 6 is a view similar to FIG. 5 illustrating a still further step inthe assembly of the foldable boat;

FIG. 7 illustrates the manner in which toggles are used to securevarious of the frame members;

FIG. 8 is a cross-sectional view taken in the direction of arrows 88 ofFIG. 7;

FIG. 9 is a longitudinal cross-section of an assembled, foldable boataccording to this invention, taken along the centre of the boat fromfore to aft thereof;

FIG. 10 is a view of the underside of an assembled, foldable boataccording to this invention, showing the cooperation of the frame andflexible cover therefor; and

FIG. 11 is a perspective, partially exploded view showing an alternativefeature of the foldable boat according to this invention, whereby theboat may be adapted to be used as a sail boat.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A foldable boat is showngenerally at in the Figures. Referring to FIG. 1, there is shown a boathaving a pair of sides 12 and 14; a nose 16; front, centre and rearthwarts 18, 20 and 22 respectively; a keel 24; a transom plate 26 and atransom 28; a nose frame member 30; and a flexible skin or cover whichis indicated generally at 32. The flexible cover 32 is attached to thesides 12 and 14 at the forward end of each and on the outer side of eachso as to provide a substantially watertight nose 16 for the boat, asdiscussed hereafter. A moulding 34 may be secured to the sides 12 or 14along the edge of the flexible cover 32, both for purposes of appearanceand to provide a secure and abrasion proof edging for the flexible cover32. As will be seen hereafter, the flexible cover 32 is attached alongthe length of each of the sides and between the aft end of each of thesides 12 and 14 so that it lies outside transom 28 when the transom isin place and secured to the transom plate 26. Floor boards indicatedgenerally at 36 and 38 are placed along the bottom of the boat 10. Apair of oar locks 40 may be conveniently attached to the upper edges ofthe sides 12 and 14.

The foldable boat 10 is shown in FIG. 2 in its collapsed or unassembledcondition. A carrying case 42 having handles 44 is shown in associationwith the unassembled boat 10 in FIG. 2. The carrying case 42 may be madeof any convenient fabric such as canvas or plastic; or it may be madefrom netting, bindings, etc.

The foldable boat 10 of this invention including any alternativeembodiments such as the sailing version discussed hereafter inassociation with FIG. 1 1 relies for its strength, when assembled, onthe combination of the frame and the flexible cover. The principalcomponent of the frame, on which the remainder of the frame is built upin one way or another as discussed hereafter, is the substantially rigidkeel 24 which extends from fore to aft of the boat; i.e., the keel 24extends from the .nose 16 of the transom 28, or at least to the transomplate 26 as discussed hereafter.

The keel 24 comprises a structural member usually made of wood which issubstantially rigid and whose length is substantially the full length ofthe boat. The keel may, as required, be collapsible with such connectingmeans as pin means so that, when reassembled, it is substantially rigid.In any event, a nose frame member 30 extends upwardly from the keel atits forward end, and a transom plate 26 is rigidly secured or adapted tobe rigidly secured to the rear or aft end of the keel 24. It will beseen that when the foldable boat is assembled the sides 12 and 14 aresupported from the keel by pin means through the nose frame member 30 attheir forward end and by the rear thwart 22 and supporting meanstherefor at their aft end; so that the transom 28 extends between theaft ends of the sides 12 and 14 above the bottom of the boat which isthen defined by the flexible cover 32 on the outside of the keel 24, thesides 12 and 14 and the transom 28.

It has been remarked that the foldable boat of this invention is easilyassembled without special tools, and the assembly of the boat isdiscussed hereafter in association with the drawings, particularly FIGS.3 to 8.

The unassembled boat may have an appearance somewhat as shown in FIG. 2;and comprises several different and separable components, as follows.Each of the floor boards 36 and 38 is separate from the rest of thestructure as are each of the thwarts 18, 20 and 22, and the transom 28.In the embodiment illustrated, the remaining frame members including thekeel 24, the nose frame member 30 and the transom plate 26, the sides 12and 14 and the flexible cover 32 are preassembled as one foldable andintegral component of the entire boat structure. Thus, each of theseparable components is removed from the packaged, unassembled boat,thereby leaving the sides/keel/cover combination as the starting pointfrom which the foldable boat is assembled.

It will be noted from FIGS. 1, 2 and 3 that the forward ends 46 and 48of sides 12 and 14 respectively do not extend fully to the nose 16 ofthe boat, but rather they lie on either side of the upwardly extendingnose frame member 30. The sides are secured to each other by pin means50 which are passed through holes 52 in the nose frame member 30, andwhich have heads 54 at each end thereof. The head 54 at either end of apin 50 can be a nut which is burred to the end of a bolt, or otherwiseas may be convenient. In any event, it will be seen that the sides 12and 14 are loosely held with respect to the nose frame member 30; exceptthat their elevation with respect to the nose frame member 30 andtherefore with respect to the keel 24 is fixed by the pins 50. It willbe seen that as the sides 12 and 14 are flexed and spread as discussedhereafter the pin means 50 act to prevent the forward ends 46 and 48 ofthe sides from spreading, so that a pinching action of the front ends 46and 48 of the sides against the nose frame member 30 begins to develop.The length of the pins 50 may be chosen to assure that the front ends 46and 48 of the sides 12 and 14 are sufficiently well secured against thesides of the nose frame member 30 without undue stress in the sidemembers or the nose frame member. It will be noted that the flexiblecover 32 extends up the nose 16 of the boat 10, and around the front endof the nose frame member 30, past the heads 54 of the pins 50, and isthen secured to the outside surfaces of the side members 12 and 14. Theflexible cover, of course, extends beneath the boat and towards the rearthereof, so that a substantially watertight nose is provided for theboat. This is particularly illustrated in FIG. 3.

Turning to FIG. 4, it will be noted that the keel 24 may include keclmembers 25 and 27 which are rigidly secured to the flexible cover 32. Inany event, the flexible cover 32 is secured to the keel 24 so that itdoes not shift sideways or lengthwise with respect to the keel, and sothat the bottom shapeof the boat when assembled can be defined by theco-operation of the boat frame, including the keel and sides togetherwith the flexible cover.

, A reinforcing plate 56 may be secured to the inner surface of each ofthe sides 12 and 14. There is also secured to the inner surface of eachof the sides 12 and 14 a series of supporting lugs and toggles for thethwarts and floorboards; and the purpose of each of the varioussupporting lugs and toggles is described hereafter as the assembly of afoldable boat according to this invention is explained.

A horizontal support lug 58, a vertical support lug 60 and a toggle 62are installed on the inside of each of the sides 12 and 14 near theforward ends thereof. During the initial stages of the assembly of thefoldable boat 10, the sides 12 and 14 are spread apart, and the foldingfront thwart 18 is placed with its lower, outer ends above thehorizontal lugs 58. It will be noted that the thwart 18 comprises anupper (or first) plate 64 and a pair of lower (or second) plates 66 and68 which are hinged at 70; and the lower plate 66 is rigidly secured tothe underside of the upper plate 64 at one end thereof. With the ends ofthe plates 66 and 64 at the one side and the end of plate 68 at theother, as illustrated in FIG. 4, downward pressure at the end 72 ofplate 64 such as by the hand 74 in the direction of arrow 76 has theeffect of forcing the side members 12 and 14 apart. The material of theplates 66 and 68 usually wood is pute in compression, lengthwise,between the sides 12 and 14, thereby forcing the sides apart as atarrows 78 and 80. The length of the toggles 62 is such that, when theyare placed in the upright position as shown in FIG. 1, the thickness ofplate 64 overlying either of the plates 66 or 68 is accommodated betweenthe lower end of the toggles 62 and the upper side of the horizontal lug58; or, in other words, thwart 18 is secured between the lugs 58 andtoggles 62. The vertical lug 60 acts as a stop so as to position thefolding front thwart l8 lengthwise in the boat. Thus, the spread of thesides 12 and 14 due to the force exerted outwardly upon them by thefolding thwart 18 can be predetermined by dimensioning the length of theplates 64, 66, and 68, shaping their outerends accordingly, and properlypositioning the lugs 58 and 60.

The rear or aft ends of the sides 12 and 14 are properly spaced by thetransom 28 which is adapted to fit down into slotted lugs 82, one ofwhich is secured at the aft end of each of the side members 12 and 14.The length of transom 28, and the angle at which the outer ends of thetransom 28 are cut, are chosen so as to define the rearmost profileviewed lengthwise of the assembled boat.

Thus, the transom 28 is pushed down into the slotted lugs 82 asindicated by arrows 84 and the aft ends of the sides 12 and 14 areforced apart as at arrows 86 and 88 respectively.

It should be remarked that the sequence in which the steps of placingthe outer ends of the transom 28 in the slotted lugs 82, and placing thefolding front thwart 18 in its position, may be varied.

It will be noted that, at this stage, the sideways spacing of sidemembers 12 and 14 is more or less established, at least at the transom28 and the front thwart 18, but that the lower edges of the sides 12 and14 are substantially-in the same plane as the keel 24. Also, the transomplate 26, which is supported above the keel 24 by an upwardly extendingaft support member 90, is elevated above the transom 28. The flexiblefabric cover 32 lying across the bottom of the boat is loose andconvoluted or folded. However, the transom 28 is adapted to be picked uptogether with the sides 12 and 14, and keyed onto the transom plate 26bykeying lugs 92. A pin 94 is placed through the transom plate 26 and intothe transom 28, so as to fix the transom in its upper position. At thesame time, the sides 12 and 14 are secured upwardly as indicated atarrows 96 and 98 by placing the rear thwart 22 in the horizontal slot100 of slotted lugs 102 which are secured to the inner surface of theside members 12 and 14 near the aft end of each. The thwart 22 is pushedbackwards as at arrow 104 so that its outer ends enter the slots 100 ofthe lugs 102. The thwart 22 is supported from underneath by the aftsupport member 90 cooperating with a supporting section 106 beneath thethwart 22.

Referring briefly to FIG. 10, it can be seen that the keel 24 definesthe lowermost part of the boat 10, that the sides 12 and 14 (14 notshown) and the transom 28 define the sides and rear of the boat (alongwith the nose 16 as discussed above); and the flexible cover 32 actingin cooperation with the sides and keel defines the bottom of the boat.It will be noted further that, due to the tensioning forces in theflexible cover, especially as it is acted upon by forces of reaction inthe water developed across its surface as the boat sits or moves throughthe water, the bottom of the boat assumes a double curvature bothdownwardly and rearwardly.

Because the bottom of the boat is comprised of the flexible coverattached to the rigid keel and the lower edges of each of the sides, aset of floorboards is placed across the bottom and is supported by thekeel along the lengthwise centre of the boat and by supporting lugs atthe lower edges of the sides 12 and 14 at the outer edges of the boat.Therefore, a plurality of supporting lugs 108 and toggles 110 are placedalong the lower edges of the sides 12 and 14 to support the floorboardsin the usual fashion. The floorboards may be slatted, as indicated inFIGS. 1 and 2, or they may be solid with sufficient allowance madetherein for drainage of rain, splash, etc. The sideways thrust againstthe lower edges of the sides of the boat is therefore taken by thefloorboards and transferred to the keel. Substantial rigidity of theboat is therefore assured.

FIGS. 7 and 8 illustrate a toggle and the manner in which it may besecured to one of the sides. Because various reference numerals havebeen used in the discussion above with respect to specific toggles, thetoggle illustrated in FIGS. 7 and 8 is referred to generally as toggle112, which acts against framing member 114 which might be a thwart on afloorboard, and the toggle is shown secured to side 13. An insert 116 isplaced in a suitable recess drilled in the outside surface of the sides13, and the insert may conveniently be of such material as neoprene orbrass. A bolt 118 is countersunk with its head 120 received by theinsert116, and the bolt 118 extends through the side 13 and the toggle 112 toa nut 122. The nut is burred at the end of the bolt so that the toggle 112 can swing in a pivotting maninner surface of the side 13. Thus, theinsert 116 acts as a bearing against theunderside of the head 120 of thebolt 118, and the pivoting action of the toggle is assured.

FIG. 9 is a sideways view of an assembled boat 10 in accordance withthis invention, and havingspecific assembly details as discussed above.It should also be noted that the central thwart 20 is supported on aframe member 128 which extends upwardly from the keel 24; and it is heldat its outer ends between vertical lugs 130 and horizontal lug 132 bytoggle 134. Each of the other structural features of the frame of thefoldable boat according to this invention, as discussed above, is foundin FIG. 9; and it is clear from that Figure that the transom 28 does notextend downwards to the keel. Therefore, the structural strength of thefoldable boat 10 is derived from the frame and the flexible cover 32over the frame, including the transom 28 and the keel 24. However, itshould also be noted that a rigid backbone for the boat 10 exists fromthe nose frame member 30 through the keel 24 and the aft support 90 tothe transom plate 26. Therefore, the foldable boat 10 is adapted tosupport an outboard engine which would be mounted to the boat in theusual way, and secured to the transom plate 26. The rigidity of the boatwhen it might be subjected to a pitching motion.

FIG. 11 illustrates an additional feature whereby the foldable boat 10as discussed above can be adapted to be used as a sailing boat. Thus thealternative sail boat embodiment of the foldable boat according to thisinvention comprises the same frame and flexible cover as discussedabove, with the addition of a centreboard and casing therefor and amounting for a mast. Therefore, a withdrawable centreboard 136 having anupper plate 138 across its top edge is adapted to be received into acentreboard casing 140. The casing extends forwardly from beneath thecentre thwart 20, and has sufficient height that water will not beducted into the boat when the centreboard 136 is withdrawn. Thecentreboard casing 140 is also slatted rearwardly to prevent water fromentering it as the boat moves forward and the centreboard 136 iswithdrawn. A socket 142 is secured to the upper side of the keel 24 sothat the lower end of a mast 144 can pass through a suitable opening 146provided in the front thwart l8, and be retained thereby. A sailingversion of the boat 10 described above is therefore provided, having amovable centreboard which can be raised and lowered from above the keel,and a mast. Suitable rigging for the mast is provided, and a tiller isplaced over the transom in the usual manner.

A foldable boat has been described which has a substantially rigid keelalong its entire length, which keel supports the transom and the nose ofthe boat, and having means so that the sides of the boat are supportedfrom their fore and aft ends. A flexible cover is placed over the nose,keel, transom, and sides, and cooperates therewith to form a boat havinga contoured bottom. The framing members, including the keel, thwart,transom, nose, floorboards, etc., may conveniently be made from wood orother suitable material. The flexible cover may be made from a bondedfabric having a rubber or plastic coating over woven glass fibres,having sufficient strength to withstand the tension forces exerted in itas a loaded boat moves in the water. Suitably, the flexible cover ischosen so as to have sufficient abrasion resistance, tear strength,etc., as to be practical.

The thwarts 18, and 22 may each operate as a thrust means across thewidth of the boat between the sides thereof; and in particular, betweenthe upper edges of the sides. Thus, each of the thwarts may act as athrust means to maintain the spacing of the sides in the area of thethwart. In the sailing version of the foldable boat according to thisinvention, either or both of thwarts 20 and 18 may be replaced by otherthrust means, specifically a bulkhead whose general construction andoperation would be similar to those of thwart l8 discussed above, exceptthat the bulkhead would have its major plane vertical rather thanhorizontal.

With suitable choice of materials, the dimensions of a foldable boataccording to this invention may range from a toy several inches longto aboat in excess of 20 feet. As mentioned, the foldable boat of thisinvention can be powered by an outboard engine of conventional type,including outboard engines whose power is in excess of 7.5 HP. Thefoldable boat can be assembled in just a few minutes (usually less than10 minutes) without any special or additional tools; and in itscollapsed state, the foldable boat is light enough that it can becarried easily by one person.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A foldable boat comprising a frame and a flexible cover therefor;

said frame comprising a substantially rigid keel adapted to extend fromfore to aft of said boat, a transom plate adapted to be rigidly securedto the aft end of said keel, an upwardly extending nose frame memberadapted to be rigidly secured to the fore end of said keel, a pair ofsides capable of being flexed and each loosely attached at its forwardend to said nose frame member, a transom adapted to be securely andremovably attached near its crosswise centre .to said transom plate,means to secure the aft end of each of saidsides to a respective outerend of said transom, at least one thwart means across the width of saidboat between the upper edges of said pair of sides; and floorboard meansadapted to be placed across the bottom of said boat when said pair ofsides are flexed outwardly and secured in their flexed position by saidtransom and said at least one thwart means, said floorboard means beingsupported by said keel and by supporting lugs secured near the bottomedge of "each of said pair of sides; 1

said flexible cover being adapted to attach to said pair of sides at theforward end of each on the outer side thereof so as to provide asubstantially watertight nose for said boat; said flexible cover beingfurther attached to each of said sides along the length thereof, andbetween the aft end of said sides so that it lies outside said transomwhen said transom is secured to said transom plate and to the aft endsof said sides.

2. The foldable boat of claim 1, wherein:

said means to secure the aft end of each of said sides to a respectiveouter end of said transom comprises an upwardly extending support memberrigidly secured to the upper side of said keel at the aft end thereof,thwart means adapted to be supported by said support members; and meansto secure each of the outer ends of said thwart means to one of saidsides, respectively, near its aft end; so that said support membersupports said thwart, and the outer ends of said thwart support said aftends of said sides. I

3. The foldable boat of claim 1 further including means adapted toreceive a movable centreboard so that said centreboard may extend belowsaid keel'and may be raised and lowered from above said keel.

4. The foldable boat of claim 1 wherein at least one thwart meanscomprises an upper plate and a pair of hinged lower plates, one of whichis secured to said upper plate and whose combined length issubstantially equal to the length of the upper plate.

t t k

1. A foldable boat comprising a frame and a flexible cover therefor;said frame comprising a substantially rigid keel adapted to extend fromfore to aft of said boat, a transom plate adapted to be rigidly securedto the aft end of said keel, an upwardly extending nose frame memberadapted to be rigidly secured to the fore end of said keel, a pair ofsides capable of being flexed and each loosely attached at its forwardend to said nose frame member, a transom adapted to be securely andremovably attached near its crosswise centre to said transom plate,means to secure the aft end of each of said sides to a respective outerend of said transom, at least one thwart means across the width of saidboat between the upper edges of said pair of sides; and floorboard meansadapted to be placed across the bottom of said boat when said pair ofsides are flexed outwardly and secured in their flexed position by saidtransom and said at least one thwart means, said floorboard means beingsupported by said keel and by supporting lugs secured near the bottomedge of each of said pair of sides; said flexible cover being adapted toattach to said pair of sides at the forward end of each on the outerside thereof so as to provide a substantially water-tight nose for saidboat; said flexible cover being further attached to each of said sidesalong the length thereof, and between the aft end of said sides so thatit lies outside said transom when said transom is secured to saidtransom plate and to the aft ends of said sides.
 2. The foldable boat ofclaim 1, wherein: said means to secure the aft end of each of said sidesto a respectiVe outer end of said transom comprises an upwardlyextending support member rigidly secured to the upper side of said keelat the aft end thereof, thwart means adapted to be supported by saidsupport members; and means to secure each of the outer ends of saidthwart means to one of said sides, respectively, near its aft end; sothat said support member supports said thwart, and the outer ends ofsaid thwart support said aft ends of said sides.
 3. The foldable boat ofclaim 1 further including means adapted to receive a movable centreboardso that said centreboard may extend below said keel and may be raisedand lowered from above said keel.
 4. The foldable boat of claim 1wherein at least one thwart means comprises an upper plate and a pair ofhinged lower plates, one of which is secured to said upper plate andwhose combined length is substantially equal to the length of the upperplate.